add captcha
consume captcha in login form
using https in captcha
add backdoor to captcha, in case of aliyun cannot connect to api.recaptcha.net sometime
make sure the connecting trial should be done in 5 seconds
do not blame school id if it did not provide one for creating or updating child
do not blame school id if it did not provide one when updating child
cannot assume childinfo always includes school id
revert reCaptcha back